Certain known dissection devices include a ring or hook attached to a shaft that extends axially for operation as a dissection tool. Such dissection tools engage a vessel to be dissected, e.g., the saphenous vein, and are pushed and pulled to separate the vessel from surrounding connecting tissue. Devices of these types are disclosed in the literature (see, for example, U.S. Pat. Nos. 5,591,183 and 5,601,581).
Such devices commonly looped around a vessel during its dissection within narrow confines of a small working cavity about the vein. As vessel branches and tributaries are encountered, the ring or loop may have to be removed from the working cavity and reintroduced at a position on the other side of the branch or tributary in order to avoid avulsing such side branches. Since a harvested vessel such as the saphenous vein will be required to withstand arterial pressure without leakage (e.g., in coronary artery bypass surgery), such side branches or tributaries are ligated with sutures or vascular clips to prevent leakage. If avulsion of a side branch occurs close to the surface of the harvested vessel, the resultant defect in the harvested vessel must be repaired, typically with multiple stitches of fine suture. Such repair is tedious and the suture repair may decrease lumen size of the bypass, leading to premature occlusion.
Manipulating such known ring and hook type dissection probes about a vessel of interest is made more difficult by the limited space available within a working cavity at the surgical site. Although the ring or hook may be lifted to disengage from the vessel, if the vessel lies near a margin or boundary of the working cavity then insufficient space may be available to enable the ring or hook to be disengaged from the vessel. Continued effort to disengage the dissection ring may lead to side branch avulsion or injury to the vessel of interest attributable to lacerations and excessive stretching.